Hall effect device related circuitry has been used for a variety of purposes. U.S. Pat. No. 4,156,191, issued to Knight, et al. on May 22, 1979, discloses an apparatus for adjusting the magnetic coupling between a Hall effect device and an operating magnet. U.S. Pat. No. 4,190,799, issued to Miller, et al. on Feb. 26, 1980, discloses a method for measuring the magnitude and sign of the Hall angle of the material of a wafer. U.S. Pat. No. 4,270,087, issued to A. K. Littwin on May 26, 1981, discloses an apparatus for testing permanent magnets using electromagnets and Hall sensors. U.S. Pat. No. 4,084,135, issued to R. S. Enabnit on Apr. 11, 1978, discloses a system and method for checking the sensitivity and performance of an electromagnetic field variation detector. Also, U.S. Pat. No. 4,230,987, issued to G. Mordwinkin on Oct. 28, 1980, discloses a digital eddy current apparatus for generating metallurgical signatures and monitoring metallurgical contents of an electrically conductive material.
While the circuits disclosed in these patents are related to magnetic field or Hall effect devices, none of these patents discloses a method for monitoring the tolerance of the operate and release points of a Hall effect device.
Accordingly, it is the object of the present invention to provide a novel test circuit which monitors the operate and release points of a Hall effect device without utilizing complex timing circuitry.